Gardener’s Corner
Chris Smith, the community coordinator for Sow True Seed—an Asheville-based company that specializes in open-pollinated, heirloom, and organic seeds—answers common gardening questions in this regular column for Smoky Mountain Living.
Managing tomatoes for health and productivity
When growing tomatoes, it can sometimes feel like we are simply trying to keep the plants alive for long enough to produce a ripe fruit. All our efforts are pitted against the innumerable pests and diseases that we know will always win and claim our tomato plants before their time.
Here are some tools for healthy tomato maintenance:
Airflow and sunlight are your friends This begins with plant spacing and positioning (wide and in full sun), but we may already be too late for that. It can continue with good pruning and staking or trellising. Our aim is to encourage a single well supported vine with fruiting branches, but tomatoes can quickly devolve into multi-stemmed rambunctious messes. I understand, it can be hard to chop off a branch that could bare fruit. But trust me, in the long run, a controlled tomato plant will yield a healthier plant and more tomatoes.
Humidity and splashed soil are not your friends You may not be able to control the humidity, but you can avoid soaking the leaves when the plants need watering. Water the roots directly, but be careful to avoid splashing soil up onto the leaves. Many of the common diseases are soil born and the splashed soil will quickly infect your plants. Straw mulch around the base of the plants can help. Pruning and support will prevent the lower branches from touching the soil.
Tomatoes are hungry and thirsty Blossom end rot is a common annoyance where a beautifully formed fruit rots at the blossom end. It is due to a calcium deficiency which is as likely to be poor calcium uptake due to drought conditions as much as low calcium in the soil (calcium is very important and I always plant my tomatoes with a handful of crushed egg shells to combat calcium deficiency). Giving your tomatoes a well rounded feeding a couple of times through the growing season will help with healthy plants. Phosphorus helps with root and flower production and potassium is as important as nitrogen through fruiting.
Be attentive The tomato hornworm can chew chunks of your tomatoes, grow large and fat and you’ll never see it. They camouflage well with the foliage. When you do see one you’ll be shocked that you’d missed it for so long! But don’t go straight for pesticides, give nature a chance. There is a natural predator of the tomato hornworm—a tiny parasitic wasp that lays its eggs in the hornworm and kills it. The eggs look like grains of rice and this is one of nature’s checks and balances. If I find them I also like plucking them off and feeding them to my ducks! When (and it is always when) diseases come, remove and destroy the diseased leaves or fruit straight away. As time progresses remove the whole plant to prevent the spread to neighboring plants. Remember you can eat green tomatoes, and if the fruit is mature enough it can finish ripening off the vine. If you’re interested in specific disease diagnostics then your local cooperative extension service should be able to help.
What flowers can I still plant now?
Don’t forget the flowers! Flowers add beauty, but they also add essential habitat for our climate-impacted declining insect populations. By supporting pollinators and beneficial insects we can increase vegetable yields and control pests with natural predators.
When deciding to plant anything later in the season, you’ll need to work out how many frost free days you have left to grow stuff. Take your average first frost date for your area and work out how many frost free days you have left i.e. let’s says it’s June 30 and your average first frost is Oct 15, that’s 112 frost free days. So, anything less than 97 days to harvest has a good chance of blooming. The heat of summer often speeds up growth, if it doesn’t fry the seedlings (make sure to protect the young and tender seedlings), although the shorter days and cooler temps in fall can slow down growth. With flowers the days to harvest generally means the days to first bloom. Here are a couple of varieties you can still plant through the end of June:
- Dwarf Sunspot Sunflower (80 days) This sunflower doesn’t get very tall before putting on impressive flowers. You’ll get magnificent 10” blooms with bright yellow petals on 2’ tall plants.
- Cosmos, Bright Lights (75-90 days) A showy, graceful annual with 3’ tall sunset-orange, red and yellow double flowers that attract butterflies. With tall stems, cosmos makes an excellent cut flower.
- Zinnia, California Giants Mix (80-90 days) All Zinnia’s are the gift that keep on giving! If you keep them deadheaded (cutting off the old flowers) they will continue to blossom all summer long, and often well into fall.
You also don’t need to be limited to traditional cut flowers. I’ll throw buckwheat out all through summer and it’ll often be up and blooming within 6-8 weeks. Buckwheat is generally used as a cover crop, but the bees love the flowers. Borage will flower in 50-60 days and is another great bee feed crop, not to mention being an edible flower for us humans. On the edible flower train of thought, nasturtiums can flower in 50-70 days, depending on variety, and the leaves and flowers are edible. Let’s also acknowledge climate change and its effect on predictable weather patterns. I’ve been growing in Western North Carolina for 5 seasons now and no one season has been the same. Planting a wide diversity of flowers and food is your best chance for success.